This invention relates to an apparatus for use in controlling the flow of process fluids and/or the monitoring of fluid properties. These fluids may be gaseous, vapor or liquid. The controlled process fluid may either be transferring its power to some other device or it may be in transit to other destinations.
The petroleum and chemical process, power generation, aerospace, and transportation industries require high reliability in emergency shutdown, safety, and critical control and monitoring systems. Conventional multiposition valves and manifolds, currently available, are not capable of simultaneously isolating and connecting both the inlet and outlet ports of parallel fluid control devices, as a single unit. When a fluid control device, such as a valve, is in need of repair, the entire process line containing that valve must often be shut down. Such shutdowns, using prior art valves and lines, cause a loss in manufacturing time, and often higher wear on equipment.
Several valves have been developed in the prior art to prevent the shutdown of process lines. U.S. Pat. No. 2,570,897, entitled "SHUTTLE VALVE," to Winchester, discloses a switching valve operated by hydraulic fluid, for controlling the amount of fluid which is sent to a particular port. U.S. Pat. No. 3,380,479, entitled "VALVE ASSEMBLY AND ACTUATING LINKAGE THEREFOR," to Bassan et al., discloses a valve stem assembly comprising bellows valves. U.S. Pat. No. 4,501,295, entitled "TRANSFER VALVE," to Williams et al., discloses a multiple-port switching valve device for large lines. The '295 patent discloses a valve stem assembly containing multiple, complex parts. All of these prior art devices are complicated to manufacture and often difficult to operate.
Accordingly, it is an object of this invention to provide a reliable apparatus for isolating at least one fluid flow circuit without interrupting the overall function of the control or measurement system or process flow.
It is another object of the invention to provide an apparatus which is easy and inexpensive to manufacture and easy to operate.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description to follow, taken in conjunction with the accompanying drawing.